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Hi,<br>
it looks like a memory interface problem. This is a typical issue
with FPGA-based PPC systems.<br>
You should check/monitor carefully the hardware :<br>
- power supplies<br>
- memory controller configuration (RAS, CAS, banks...)<br>
- timing of pins connected to external memory<br>
Prior to boot a linux kernel, you should test your board with an
exhaustive standalone test program running from internal BRAM. In
particular, you should run an intensive test of your external memory
with cache enabled. Cache must be configured in copy back mode and
test code must be written so that it causes a lot of cache misses.<br>
Hope this helps.<br>
<br>
Manu<br>
<br>
Le 31/12/2011 05:15, Wang, Junhua H. (NSN - CN/Hangzhou) a écrit :
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<title>Ask a technical problem happened on PPC board</title>
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<p dir="LTR"><span lang="en-us"><font color="#1f497d"
face="Calibri">HI, all:</font></span><span lang="en-us"></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"></span><span
lang="en-us"></span><span lang="en-us"><font face="Calibri"> </font>
<font face="Calibri">Sorry to disturb all of you in the
linuxppc-dev mail group. I am a new member from linuxppc-dev
from China, and I have a very weird problem, it have been
bothering me for a long time. I will be very grateful if
you can help me to analyse it.</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri"> 1) Problem</font> <font face="Calibri">description:</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">a) FRIU(a circuit board) unit is a
ppc(powerpc) unit, 256 M bytes Ram, bootloader is uboot,
kernel linux-2.6.21 filesystem: initramfs</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">The main problem is that when kernel start up
and mount initramfs, run the init process(pid 1), when the
proc</font><font face="Calibri">ess(init) write file(20 M
bytes) to filesystem(initramfs),</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">sometimes it will find some data modified
when check the file</font><font face="Calibri">’</font><font
face="Calibri">s contents by read it. </font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">b) I have write a test init process which
will write 20 Mbytes data(0xFF) to "/TEST0.IMG" and check
it's conten</font><font face="Calibri">ts. Sometimes, the
contents will by modified.</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">c) Here is the test procedure: </font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">Uboot download linux kernel and initramfs
--> cmd "bootm" to start linux --></font></span><span
lang="en-us"></span><span lang="en-us"> <font color="#ff0000"
face="Calibri">after kernel start complete, mount initramfs,
run init process(pid 1)</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"></span><span
lang="en-us"><font face="Calibri">--> It will write 20
Mbytes dat</font><font face="Calibri">a(0XFF) to 'TEST0.IMG'
and check it's contents, If there is error, the error data
will be printed.</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">2) Error data:</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">a) Every time the error happened, a pair of
data modified:</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">first place: </font></span><span lang="en-us"></span><span
lang="en-us"> <font color="#ff0000" face="Calibri">1C 00 FF
FF FF FF FF FF 00 00 00 040 80 ..</font></span><span
lang="en-us"></span><span lang="en-us">.</span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">Second place:</font></span><span lang="en-us"></span><span
lang="en-us"> <font color="#ff0000" face="Calibri">FF FF FF F</font><font
color="#ff0000" face="Calibri">F FF FF 00 A0 ....</font></span><span
lang="en-us"></span><span lang="en-us"></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">Sometimes, there will be 2 pair of data
modified.</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">b) The error happens not very often, but it
happens sometime.</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">3)</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">Could you give me some advice on how to
investigate it or which part you think will have problem? </font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">Thanks very much!</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">Used</font><font face="Calibri"> kernel:
linux-2.6.21</font></span><span lang="en-us"></span><span
lang="en-us"></span><span lang="en-us"><font color="#000000"
face="SimSun" size="2"> <<init process write_read
file(20Mbytes) error2.txt>> </font></span><span
lang="en-us"></span><span lang="en-us"></span><span
lang="en-us"></span><span lang="en-us"></span><span
lang="en-us"><font color="#000000" face="SimSun" size="2">
<<init process write_read file(20Mbytes)
error.txt>> </font></span><span lang="en-us"></span><span
lang="en-us"></span><span lang="en-us"></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">Br,</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"><font
face="Calibri">Wang Junhua</font></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"></span></p>
<p dir="LTR"><span lang="en-us"></span><span lang="en-us"></span><b><span
lang="en-us"></span><span lang="en-us"><font color="#808080"
face="Arial Black">Wang Junhua (Jonny)</font></span></b><span
lang="en-us"></span><span lang="en-us"></span><i><span
lang="en-us"></span></i></p>
<p dir="LTR"><i><span lang="en-us"><font color="#808080"
face="Arial">-----------------------------------------</font></span></i></p>
<p dir="LTR"><i><span lang="en-us"><font color="#808080"
face="Arial">LINDX</font></span></i></p>
<p dir="LTR"><i><span lang="en-us"><font color="#808080"
face="Arial">DX 200 R&D HZ Area E </font></span></i></p>
<p dir="LTR"><i><span lang="en-us"><font color="#808080"
face="Arial">MP: +8615967154143</font></span></i></p>
<p dir="LTR"><i><span lang="en-us"><font color="#808080"
face="Arial">Seat:4076</font></span></i><span lang="en-us"></span><span
lang="en-us"></span><span lang="en-us"></span></p>
<p dir="LTR" align="JUSTIFY"><span lang="en-us"></span></p>
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